Biosensors are devices for sensing and detecting biomolecules and operate on the basis of electronic, electrochemical, optical, and mechanical detection principles. Biosensors that include transistors are sensors that electrically sense charges, photons, and/or mechanical properties of bio-entities or biomolecules. The detection can be performed by detecting the bio-entities or biomolecules themselves, or through interaction and reaction between specified reactants and bio-entities/biomolecules. Biosensors include BioFETs (biological field-effect transistors, biologically sensitive field-effect transistors, biologically active field-effect transistors, or bio-organic field-effect transistors), optical sensors (for example, a CMOS image sensor), electrochemical biosensors, and mass sensitive sensors (for example, with embedded piezoelectric crystals). Such biosensors can be manufactured using semiconductor processes, can quickly convert biomolecular information to electric signals, and can be easily applied to integrated circuits (ICs) and microelectromechanical systems (MEMS).
Biochips are essentially miniaturized laboratories that can perform hundreds or hundreds thousands of simultaneous biochemical reactions. Biochips can detect particular biomolecules, measure their properties, process resulting signals, and may even analyze the data directly. Biochips enable researchers to quickly screen large numbers of biological analytes for a variety of purposes, from disease diagnosis to detection of bioterrorism agents. Advanced biochips use a number of biosensors along with fluidic channels to integrate reaction, sensing and sample management. While biochips are advantageous in many respects, challenges in their fabrication and/or operation arise, for example, due to compatibility issues between the semiconductor fabrication processes, the biological applications, and restrictions and/or limits on the semiconductor fabrication processes.